FXUS63 KLBF 142045
AFDLBF

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTH PLATTE NE
245 PM CST MON DEC 14 2009

.DISCUSSION...
SHALLOW ARCTIC HIGH IS FCST TO BUILD SOUTH THROUGH NCNTL NEB AND
INTO NCNTL KS BY 12Z TUE. WRN ZONES MAY HAVE EARLY EVENING
LOWS AND SLOWLY WARMING TEMPERATURES OVERNIGHT AS SOUTH WINDS
DEVELOP THIS EVENING AND CONTINUE OVERNIGHT. EAST OF 83 AND BENEATH
THE RIDGE AXIS THE BEST GUESS IS TO UNDERCUT GUIDANCE BY 5 DEGREES OR
SO. NO SIGNIFICANT WIND CHILL EFFECT IS EXPECTED WITH LIGHT WINDS
TONIGHT BELOW 10 MPH.

TUESDAY THROUGH WEDNESDAY...GRADUAL WARMING AS THE ARCTIC HIGH
DRIFTS EAST INTO THE MIDWEST. TEMPERATURES WILL WARM THROUGH THE
TEENS AND 20S TO THE 30S AND 40S BY WEDNESDAY. THE EROSION OF THE
ARCTIC DOME SHOULD BE UNEVENTFUL WITH NO STRATUS OR DRAPE
DEVELOPING.

THURSDAY AND FRIDAY...THE ECMWF...NOGAPS AND GEM ARE IN AGREEMENT
TRACKING A PACIFIC DISTURBANCE THROUGH THE WRN HIGH PLAINS. THE
NAM12 SUGGESTED A SLIGHT CHC OF SNOW SHOWERS THURSDAY AFTERNOON AS
THE PACIFIC FRONT ENTERS WRN NEB. THE ECMWF WAS USED FOR POPS AND
QPF THURSDAY NIGHT AND FRIDAY. THIS DISTURBANCE IS EXPECTED TO DROP
NEARLY DUE SOUTH THROUGH THE HIGH PLAINS AS THE UPPER LEVEL FLOW
AMPLIFIES NORTHWARD. THIS NORMALLY PINS THE QPF WEST OF HIGHWAY 61
AND LATER FCSTS MAY HAVE TO REFINE THIS FCST ALONG AND WEST OF
HIGHWAY 61. THE GEM AND NOGAPS ARE ORIENTED MORE NW TO SE WITH THE
DISTURBANCE FAVORING SOUTHWEST NEB. THE GFS IS DRY AND HAS BEEN
DISCARDED FOR NOW AS THE OTHER MODELS HAVE BEEN COMING INTO CLOSER
AGREEMENT.

SATURDAY THROUGH MONDAY...THE ECMWF...GEFS AND NOGAPS ARE PULLING
ANOTHER ARCTIC HIGH DIRECTLY SOUTH THROUGH UPPER MIDWEST AND INTO
THE LOWER MISSOURI BASIN AND HOLDING IT THERE STATIONARY AS AN UPPER
LOW DEEPENS ACROSS THE EASTERN U.S. WHAT REMAINS TO BE DECIDED IS
THE LOCATION OF THIS LOW WHICH WILL DICTATE HOW FAR WEST AND HOW DEEP
THE ARCTIC AIR WILL BUILD ACROSS THE CNTL PLAINS. THE OFFICIAL FCST
IS FOR HIGHS IN THE 20S TO LOWER 30S. THIS IS A MIDDLE OF THE ROAD
FCST BETWEEN THE COOLER ECWMF AND WARMER GFS. NO SIGNIFICANT SNOWFALL
IS EXPECTED AT THIS TIME AS THE UPPER LEVEL FLOW IS NORTH SOUTH AND
MOISTURE APPEARS TO BE QUITE LIMITED.

&&

.AVIATION...
SKIES HAVE BECOME VFR THIS AFTERNOON AND WILL CONTINUE THROUGH THE
NIGHT. MODELS INDICATE A REDEVELOPMENT OF MVFR STRATUS IN THE
MORNING OVER SW NEBRASKA...WHICH WILL IMPACT THE KLBF TERMINAL.
FURTHER NORTH...FOR KVTN...CLOSER TO THE RIDGE OF HIGH PRESSURE...NO
STRATUS IS EXPECTED AT THIS TIME. MVFR STRATUS CAN NOT BE RULED OUT
FOR THE VTN...HOWEVER CONFIDENCE OF OCCURRENCE IS TO LOW TO MENTION
IN THE TAF AT THIS TIME. WINDS WILL BE OUT TO THE NORTH TO NORTHWEST
AROUND 10KTS UNTIL SUNSET...WHEN THE BECOME LIGHT AND VARIABLE.
WINDS SWITCH TO THE SOUTH FOR TOMORROW...ONCE MIXING OCCURS IN THE
BOUNDARY LAYER...WHICH WILL BE DELAYED IN THE PLATTE RVR VALLEY.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

CDC/MM